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Analytical solution of diffraction by planar periodic structures
Kuchařík, Jan ; Antoš, Roman (advisor) ; Ostatnický, Tomáš (referee)
In my research work, I study diffraction by planar periodic structures (diffraction grating). In the first chapter, I try to familiarize the importance of diffraction gratings in spectroscopy. The second chapter explains the basic principle of diffraction without involving difficult mathematical tools. In the third chapter, I deduce Fourier modal method from Maxwell equations, a modern mathematical approach used for calculating the electromagnetic response of diffraction. The most important part of my work consists of the fourth and fifth chapter. At first, I try to utilize Fourier modal method for deriving formulas involving just 0th and (-1)st diffraction orders. Because of the unreasonable difficulty of uncovered formulas, I decided to consider only a special case - so-called Littrow configuration, in which the solution can be superposed from symmetric and antisymmetric couples of rays. I further develop so-called Local modal method - very inaccurate, but mathematically fairly simple, and discuss its physical limitations. Whole work is finished by the sixth chapter, which compares accurate computations gained from simulation and derived analytical formulas for both methods.
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Surface plasmons in optical microstructures and their sensor applications
Adam, Pavel ; Homola, Jiří (advisor) ; Brynda, Eduard (referee) ; Richter, Ivan (referee)
Title: Surface plasmons in optical microstructures and their sensor applications Author: Pavel Adam Institute: Institute of Photonics and Electronics AS CR, v.v.i., Department of Optical Sensors Supervisor of the doctoral thesis: doc. Ing. Jiří Homola, CSc., DSc. Abstract: This work is focused on the study of surface plasmon resonance (SPR) sensor platforms based on wavelength division multiplexing (WDM) of multiple surface plasmons (SPs). These sensors are based on advanced diffraction gratings supporting either conventional or Bragg-scattered SPs, which are simultaneously excited at different wavelengths. These SPs are studied both analytically and numerically using rigorous coupled-wave analysis and an integral approach. WDM of two and three SPs is presented and followed by the method for the analysis of the resolution, noise and cross-sensitivity. This method is employed to analyze the ability of different SPR sensor platforms (supporting WDM of two SPs) to discriminate refractive index (RI) changes in a thin layer at the sensor surface from background RI changes. The WDM SPR sensors based on advanced diffraction gratings prepared by interferometric holography are developed and tested in a model biosensing experiment consisting of the layer-by-layer growth of protein multilayers. The linear WDM of two...
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Some Other Gratings: Benchmarks for Large-Area E-Beam Nanopatterning
Meluzín, Petr ; Horáček, Miroslav ; Urbánek, Michal ; Bok, Jan ; Krátký, Stanislav ; Matějka, Milan ; Chlumská, Jana ; Kolařík, Vladimír
E-beam lithography is a flexible technology for diffraction gratings origination. Nevertheless, requirements of the high optical quality of large area diffractive structures imply various severe challenges to e-beam delineating processes. This paper summarizes the e-beam process parameters that influence the quality of large area grating structures. Next, we propose some new methods to prepare diffraction gratings that were found to be useful for testing and benchmarking purposes. Those methods include single line gratings, labyrinth structures, fractional structures, tiling patterns, quasi regular filling structures and forked line structures. Various samples were prepared with the standard and newly developed e-beam patterning processes using both e-beam writers available: one with the Gaussian beam at 100 keV and another one with the shaped beam at 15 keV. Some of the results are presented further in this paper, their variants and parameters are discussed as well as their usefulness as benchmarking e-beam patterns for large area optical structures, elements and devices.
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Diffraction efficiency of surface relief gratings
Hradil, Milan
Diffraction efficiency of surface-relief gratings with various profiles is discussed. The general relation for the diffraction efficiency is derived from the Frauenhoffer approximation. The general relation is applied for several profiles. It is pointed out that shallow profiles can provide high diffraction efficiencies.
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Diffractive Optics: Analysis, Design and Fabrication of Diffractive Optical Elements
Fiala, P. ; Matějka, František ; Richter, I. ; Škereň, M.
This contribution presents results obtained in the field of diffractive optics, covering practically all aspects of the analysis, design and realization process of the diffractive optical elements (DOEs). As for the analysis, using the rigorous diffraction methods, we have recently been able to efficiently analyze various diffraction gratings. Concerning the synthesis, several design strategies have been studied and implemented for designing both binary and multi-level phase DOEs. Using the numerically computed designs, E-beam lithography technology has been chosen for fabricating both binary and multi-level phase DOEs, using the BS 600 e-beam lithographic facility at ISI AS CR. Finally, some typical examples of optical reconstructions are presented and discussed.
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